Scientists Extract RSA Key From GnuPG Using Sound of CPU

[Recursion]

Well, that's disconcerting...

http://it.slashdot.org/story/13/12/18/2122226/scientists-extract-rsa-key-from-gnupg-using-sound-of-cpu

In their research paper titled RSA Key Extraction via Low-Bandwidth Acoustic Cryptanalysis, Daniel Genkin, Adi Shamir and Eran Tromer et al. present a method for extracting decryption keys from the GnuPG security suite using an interesting side-channel attack. By analysing the acoustic sound made by the CPU they were able to extract a 4096-bit RSA key in about an hour (PDF). A modern mobile phone placed next to the computer is sufficient to carry out the attack, but up to four meters have been successfully tested using specially designed microphones.

[MannyGoldstein]

1. Mindblowing.

Thanks.

[cantbeserious]

2. We Are All Unsafe From Prying Spies And Eyes

eom

[lapfog_1]

3. I suspect this could be defeated.

What I would do is simply have the CPU perform random math calculation while doing the encryption routine (inject meaningless CPU cycles into the calculation, thus "noise" into the analysis).

while not perfect, it might make it very difficult to break via this method. However it would increase the cost (either by slowing down or using more CPU cycles) the encryption by using RSA (and likely most other public key encryption algorithms).

[Chan790]

5. The problem is that there is no actual random as far as computing concerned.

Even random number generators are not truly random. They eventually fall into complex and predictable patterns once one discerns the formula used to generate the only-seemingly-random data unless the generation of numbers is based on an external random stimuli such as radioactive decay or micro-seismic activity rather than processor computations.

http://computer.howstuffworks.com/question697.htm

[lapfog_1]

8. you misunderstood me

I would have the encryption routine, while doing actual encryption operations, select other operations at random (FFTs, etc) and run both operations at the same time (interleave the instruction streams). Just in case they can tell what part of L1 or L2 cache might be tied to what, I would flush cache at random intervals as well... and, just to confuse things further, I would randomly move chunks of memory around (in physical memory), just in case they can snoop that as well.

[Recursion]

10. Kirchoff's postulate

Always assume an attacker has access to your entire cryptosystem except for the key. If you use a software random number generator, that's included.

[jazzimov]

6. Just use a solid-state drive. nt

[lapfog_1]

9. I read the story as they are analyzing the noise that the CPU makes as it calculates the encryption

each math instruction, and the registers and circuits that do the math, might give off a signature noise, along with heat (and possibly a very small amount of light, along with the result of the calculation.

[NoOneMan]

4. Thats absolutely crazy

[Orrex]

7. Incidentally, that's basically how Gort resuscitated Klaatu after his fatal gunshot wound

Fun fact.

[AgingAmerican]

11. You think that one is weird?

Check THIS one out.

[Recursion]

12. Yeah, that was crazy

Awesome, but terrifying...